Knocking seems to be coming from the back of the Cup. You can recreate the sound each time when driving along really steady say in third and you just tap the accelerator and release and its as if something at the back of the car has gone forward with the momentum and then because the car has slowed immediately its gone back and knowcked against something. If you accellerate really smoothly then no problems its only as I say of the momentum of the car changes abrubtly.
Does anyone recognise this, I of course checked everything in the bootwell to see if anything is loose but all seems ok, seems to be something under the car at the back or something.
Cheers
Chris